Cheese making is difficult primarily due to the challenge of finding a starter culture. The starter bacteria give different cheeses their distinctive flavor. Without it, the cheese often resembles pot cheese, farmer's cheese, or cottage cheese.
For the most flavorful results, unpasteurized milk is ideal, though it can be hard to source and may require obtaining directly from a cow. Goats milk is also a good option, tasting excellent even when pasteurized.
Remember that there are thousands of cheese varieties due to thousands of variations on this basic process. Experimentation is key.